#include<bits/stdc++.h>
#define ONLINE_JUDGE
#define ll long long
#define ull unsigned long long
using namespace std;

const int N = 1e6 + 10, INF = 0x3f3f3f3f;

int n;
string a[N];
set<string> s;

void solve()
{
    cin >> n;
    for (int i = 1;i <= n;i++) cin >> a[i];

    for (int i = 1;i <= n;i++)
        for (int j = 1;j <= n;j++) {
            if (i == j) continue;
            s.insert(a[i] + a[j]);
        }
    cout << s.size();
}

signed main()
{
    // ios::sync_with_stdio(0);
    // cin.tie(0);cout.tie(0);
#ifndef ONLINE_JUDGE
    std::istringstream in(R"()");
    std::cin.rdbuf(in.rdbuf());
#endif
    int T = 1;
    //cin>>T;
    for (int i = 1;i <= T;i++) {
        solve();
    }
}